Senior Design Midterm 2

Fasteners and Threads:

  • Threaded Features: threads are specified in a thread note

  • General Fasteners: purchasing information must be given to allow the fastener to be ordered correctly

  • Major DIA: the largest diameter

  • Minor DIA: the smallest diameter

  • Depth of thread = (D-d)/2

  • Pitch DIA: the diameter at which a line cuts the spaces and threads equally

  • Pitch: the distance from a point on a screw thread to a corresponding point on the next thread (in/threads)

    • P = 1/TPI

  • Angle of thread: the angle between threads

  • TPI: threads per inch

  • Screw Axis: the longitudinal centerline

  • Lead: the distance a screw thread advances axially in one turn

 

  • Major diameter, threads per inch, and profile are the minimum information in a unified thread specification

    • Has coarse, fine and extra fine series

  • PVC - polyvinyl chloride

  • NPT: national pipe thread used for tightly sealed joints


Legal Aspects of Engineering:

 

Design for Manufacturability and assembly guidelines:

  • Simplify the design and reduce the number of parts

  • Standardize and use common parts and materials

  • Design for ease of fabrication

  • Design within process capabilities and avoid unneeded requirements

  • Mistake proof product design and assembly

  • Design for parts orientation and handling to minimize non value added manual effort and ambiguity in orienting and merging parts

  • Minimize flexible parts and interconnections

  • Design modular products to facilitate assembly with building block components and subassemblies

 

Workplace Responsibility and Rights

  • Formal policies

  • Traditions and practices

  • Personal attitudes and commitments

  • Duty of Confidentiality: duty to keep secretes from others inside and outside the organization that would be desirable by anyone

    • Assume all information is to be kept secret

  • Privileged Information: information for selected employees on a need to know basis

    • The working of the company not the products

  • Proprietary Information: important and secret information only known by the company

    • Trade secrets do not have the legal protection of patents

  • Professional Conflict of Interest: interests that might keep one from meeting obligations or duties to the employer

    • Employee is in a role that requires the exercise of good judgement

    • Employee has some additional interest that could jeopardize the execution of good judgment

  • Are to inform employers of conflicts of interest

    • Relative, contracted service, second job, travel

  • Influence Peddling: insidious form of conflict of interest where someone offers payment

  • Kickback: prearranged payments in exchange for sales to subvert the good judgment of those purchasing

  • Business Gift: small gratuity offered in the normal conduct of business

    • Something not given in secret

    • May be consumed in a day

    • Would be an appropriate gift for a causal friend

  • Extortion: threats of harm are made by a party to gain material advantage or prevent disadvantage

    • ADA insurance

    • Product tampering

    • Blackmail

  • Whistleblowing: information is conveyed about a significant moral problem in a form that is outside of the norm

    • A last resort --> document all communications

    • Actual potential harm reported is serious

    • Harm has been documented

    • Concerns have been sent to supervisors

    • Regular modes of communication have been used to the highest extent

    • Reasonable hope that this can help prevent or remedy the harm

  • Moonlighting: second paying job that hinders you from giving 100% at the job

  • Collegiality: teamwork; respect for others' professional expertise and commitment to goals

  • Authority can be executive (voted) and expert

  • The essence of leadership is the ability to inspire cooperation

 

Rights of Engineers

  • Right of professional conscience: follow the canons and codes

  • Right of conscientious refusal: cannot be forced to do things against personal standards

  • Right to recognition: monetary and recognition for contributions

  • Privacy: monitor work performance but must be informed

  • Basic Human Rights: equal opportunity, free of harassment and preferential treatment


 

Three Mile Island

  • Nuclear energy power plant in 1979

  • March 28th, 1979 it blew up and leaked everywhere

  • Most engineering accidents happen because of

    • The collusion of several circumstances that alone wouldn’t do anything

      • Plurality of causes

    • The inability to visualize the results of specific actions

    • The inability to recognize and heed warnings

    • The suspension of caution for wishful thinking

  • Control indicators should always indicate if an order has been executed and not just attempted

    • Always trust your instruments

  • The machine and human interface must accommodate the limitations of both parties

  • Too much information is worse than not enough

  • To be useful information must be timely

  • Over complicated designs are a sign of immature and over confident designers

    • Occums rule: keep it simple

 

Kansas City Hyatt:

  • 1976 by Gillium Colaco International Engineers

  • Each walkway had 64000 lbs and 120ft long (skyways)

    • 2nd and 4th floors collapsed during a party

      • 114 killed 200 injured

  • Box beams were different from those that were supposed to be installed

    • 2 holes instead of one

    • Changed the load on the hole

  • Other potential failures occur before thread shear occurs

  • Shear strength is the ratio of shear to tensile strength and should be greater than 0.580

    • A washer would have prevented the failure

    • Design lacked redundancy --> no safety factor

  • It wasn’t a matter of doing something wrong, they just never did it at all

  • Imhotep: reckoning is the beginning of all knowledge

 

Lessons

  • Unresolved thing problems often mutate into people problems

  • Have respect for your own work

  • Engineering is a team sport

  • Make no snap decisions

  • Document your actions

  • The problem is not corrected until it never happens again

    • Document and learn from experiences

 

Your Money Future:

  • Roth: you pay taxes on money before investing and pay no taxes when removing money

  • Traditional: save money before taxes and pay taxes when removing money

    • Roth is better for someone early in their career

  • Premium: what you pay each month to have insurance

  • Coinsurance: percentage of the cost of your health services that you pay

    • After deductible is met

  • Don’t go to doctor often: get a lower premium and higher everything else

  • Negotiating

    • Know your worth

    • Prepare your pitch

    • Conduct negotiation by phone or video call

  • Personal Finance:

    • Think about your lifestyle goals and what you need to support these goals

    • Consider your money mindset (save vs spender)

    • Create and implement your plan

  • Pay bills on time, 401k, save, credit card debt, loans, max out Roth IRA, other debt

    • IRA: individual retirement account (7000 / yr)

  • 7 year rule: at 10% rate of return, savings will double about every 7 years

  • Look for a fee only fiduciary financial advisor